(Question) I/O Problem with Canon EOS 5DS about python-gphoto2

[J0hannB]

For any future users who have this problem, I spent days trying to figure out what was going on when my Canon EOS 6D kept running into the mysterious I/O problem while copying files. Sometimes it would happen after 5 images were copied, and sometimes I could get through up to 70 before the issue occurred. This happened to me using both python-gphoto2 and the gphoto2 command line utility.

Turns out, gphoto2 has some problems with USB 3.0 ports, that can cause this issue (since the 6D only has 2.0 capability, it is best to use a USB 2.0 port). My problem, however, came from the fact that I was running gphoto2 in Ubuntu through a VM on Windows, and had not enabled USB 2.0 support. I downloaded the VirtualBox extension pack, enabled 2.0, and haven't seen this issue since.

Hope this helps any future users!

[jim-easterbrook]

I don't know the answer, but I'd start by finding out if the problem also happens if you use just one camera. If it only happens when two cameras are in use then maybe there's some sort of bus conflict or something. Are you using multiple threads or multiple processes? I don't know if libgphoto2 is thread-safe.